git.ipfire.org Git - thirdparty/openembedded/openembedded-core-contrib.git/blob

   1 From 3239a4231ff79bf8b67b8faaf414b1667486167c Mon Sep 17 00:00:00 2001
   2 From: Andrew Burgess <andrew.burgess@embecosm.com>
   3 Date: Mon, 19 Dec 2016 15:27:59 +0000
   4 Subject: [PATCH] bfd: Improve lookup of file / line information for errors
   5
   6 When looking up file and line information (used from the linker to
   7 report error messages) if no symbol is passed in, then use the symbol
   8 list to look for a matching symbol.
   9
  10 If a matching symbol is found then use this to look up the file / line
  11 information.
  12
  13 This should improve errors when looking up file / line information for
  14 data sections.  Hopefully we should find a matching data symbol, which
  15 should, in turn (we hope) match a DW_TAG_variable in the DWARF, this
  16 should allow us to give accurate file / line errors for data symbols.
  17
  18 As the hope is to find a matching DW_TAG_variable in the DWARF then we
  19 ignore section symbols, and prefer global symbols to locals.
  20
  21 CVE: CVE-2017-8392
  22 Upstream-Status: Accepted
  23
  24 Signed-off-by: Fan Xin <fan.xin@jp.fujitsu.com>
  25 ---
  26  bfd/dwarf2.c                   | 32 ++++++++++++++++++++++++++++++++
  27  1 files changed, 32 insertions(+)
  28
  29
  30 diff --git a/bfd/dwarf2.c b/bfd/dwarf2.c
  31 index 03447a9..9bb8126 100644
  32 --- a/bfd/dwarf2.c
  33 +++ b/bfd/dwarf2.c
  34 @@ -4155,6 +4155,38 @@ _bfd_dwarf2_find_nearest_line (bfd *abfd,
  35      {
  36        BFD_ASSERT (section != NULL && functionname_ptr != NULL);
  37        addr = offset;
  38 +
  39 +      /* If we have no SYMBOL but the section we're looking at is not a
  40 +         code section, then take a look through the list of symbols to see
  41 +         if we have a symbol at the address we're looking for.  If we do
  42 +         then use this to look up line information.  This will allow us to
  43 +         give file and line results for data symbols.  We exclude code
  44 +         symbols here, if we look up a function symbol and then look up the
  45 +         line information we'll actually return the line number for the
  46 +         opening '{' rather than the function definition line.  This is
  47 +         because looking up by symbol uses the line table, in which the
  48 +         first line for a function is usually the opening '{', while
  49 +         looking up the function by section + offset uses the
  50 +         DW_AT_decl_line from the function DW_TAG_subprogram for the line,
  51 +         which will be the line of the function name.  */
  52 +      if ((section->flags & SEC_CODE) == 0)
  53 +       {
  54 +         asymbol **tmp;
  55 +
  56 +         for (tmp = symbols; (*tmp) != NULL; ++tmp)
  57 +           if ((*tmp)->the_bfd == abfd
  58 +               && (*tmp)->section == section
  59 +               && (*tmp)->value == offset
  60 +               && ((*tmp)->flags & BSF_SECTION_SYM) == 0)
  61 +             {
  62 +               symbol = *tmp;
  63 +               do_line = TRUE;
  64 +                /* For local symbols, keep going in the hope we find a
  65 +                   global.  */
  66 +                if ((symbol->flags & BSF_GLOBAL) != 0)
  67 +                  break;
  68 +             }
  69 +       }
  70      }
  71
  72    if (section->output_section)
  73 --
  74 1.9.1
  75